CORDIC-ARCTAN

[gary36]

I am looking for a verilog Code for arc tan function. I am recieving DC sine/cosine from 16 bit ADC. INput ranges for ADC are 0 to +/-5V. I need 16 bit fixed point implemetation.
Could anybody provide pointers ( btw: required for all 4 quadrants and to be implemented in FPGA)

 

[FlyingDutch]

I am looking for a verilog Code for arc tan function. I am recieving DC sine/cosine from 16 bit ADC. INput ranges for ADC are 0 to +/-5V. I need 16 bit fixed point implemetation.
Could anybody provide pointers ( btw: required for all 4 quadrants and to be implemented in FPGA)

Hello,
there is one implementation in SystemVerilog on Opencores.org:

https://opencores.org/projects/cordic_atan_iq

Regards

 

[gary36]

I tried to check with the C code and then tranlsating to verilog. Below is one. Why does this code not work?

 

[KlausST]

Hi,

Why does this code not work?

I guess you need to tell us:

* How did you test it?
* What did you expect?
* What did you see instead?

Klaus

 

[gary36]

In the code , you may notice that test angle is 30 deg ( sine theta =0.5,cos theta= 0.866). I get 43 deg instead.

 

[gary36]

Could locate the error. It is in the Tan table. Now scaled all values to Q15 and now works very well.